Configure code formatting using black

"E203 whitespace before ':'" ignored from now on, becuase [1] and [2].

[1] psf/black#544
[2] https://github.com/ambv/black#slices

Makefile

@@ -1,5 +1,5 @@
 .PHONY: lint
-lint: flake8 mypy
+lint: flake8 mypy check-format
 
 .PHONY: flake8
 flake8:
@@ -20,3 +20,13 @@ test:
 
 .PHONY: ci
 ci: test lint
+
+
+.PHONY: format
+format:
+ black .
+
+
+.PHONY: check-format
+check-format:
+ black --check .

pyproject.toml

@@ -0,0 +1,5 @@
+[tool.black]
+line-length = 110
+py36 = true
+skip_string_normalization = true
+exclude = 'clang/'

setup.cfg

@@ -5,7 +5,7 @@ application-import-names = kotlang
 # TODO go down to 105-110
 max-line-length = 115
 # Ignoring F821 because we use unquoted forward declarations in type hints (PEP 563)
-ignore = E701,F401,F821,W503
+ignore = E203,E701,F401,F821,W503
 exclude = kotlang/clang
 
 [tool:pytest]

setup.py

@@ -6,23 +6,17 @@
  name='kotlang',
  license='MIT',
  packages=['kotlang'],
- install_requires=[
- 'llvmlite>=0.23.2',
- 'click',
- ],
+ install_requires=['llvmlite>=0.23.2', 'click'],
  extras_require={
  'dev': [
+ 'black',
  'flake8',
  'flake8-import-order',
  # We need to avoid 0.650 because of https://github.com/python/mypy/pull/6097
  'mypy>=0.620,!=0.650',
  'pytest',
  'pytest-cov',
- ],
- },
- entry_points={
- 'console_scripts': [
- 'kotc = kotlang.kotc_main:main',
- ],
+ ]
  },
+ entry_points={'console_scripts': ['kotc = kotlang.kotc_main:main']},
  )